Packaged semiconductor dies, including memory chips, microprocessor chips, imager chips, and central processing units, typically include a semiconductor die mounted on a substrate and encased in a plastic protective covering. The die includes functional features, such as memory cells, processor circuits, and imager devices, as well as bond pads electrically connected to the functional features. The bond pads can be electrically connected to terminals outside the protective covering to allow the die to be connected to higher level circuitry.
Semiconductor manufacturers continually reduce the size of die packages and other semiconductor components to fit within the space constraints of electronic devices, while also increasing the functional capacity of each package to meet operating parameters. One approach for increasing the processing power of a semiconductor package without substantially increasing the surface area covered by the package (i.e., the package's “footprint”) is to vertically stack multiple semiconductor dies on top of one another in a single package. The dies in such vertically-stacked packages can be interconnected by electrically coupling the bond pads of the individual dies with the bond pads of adjacent dies using through-silicon vias (TSVs). In vertically stacked packages, the heat generated is difficult to dissipate, which increases the operating temperatures of the individual dies, the junctions therebetween, and the package as a whole. Another approach for increasing processor power while decreasing overall assembly size is to move die packages and other semiconductor devices closer to each other. In such applications, heat from adjacent packages can increase the overall operating temperature of each die package. These size-reduction efforts can cause the die packages to reach temperatures above their maximum operating temperatures in many types of device.